I use my own lists, extracted partly from British Royal Navy Shiplist, and partly from my roleplay imagination.
For example, that's from my last 2 campaings:
Main battle ships
Sovereign, Majestic, Superb, Redoubtable, Furious, Terrible, Formidable, Renown, Victorious, Triumphant
Defence, Vanguard, Repulse, Vengeance, Revenge, Nemesis, Trident, Sceptre, Warspite, Orion, Colossus
Courageous, Audacious, Intrepid, Undaunted, Resolute, Valiant, Inflexible, Fearless, Dauntless, Steadfast, Indomitable, Daring, Dreadnought
Tiger, Lion, Glorious, Illustrious, HyperionCarriers
Europe, America, Africa, India, Orient, Oceania
Void, Infinity, Horizon, Veil
Constitution, Concord, Codex, CommonwealthCruisers
Cyrus, Hannibal, Caesar, Attila, Temujin, Saladin
Dragon, Wyvern, Hydra, Medusa, Manticore
Centaur, Condor, Crescent
Amazon, Amethyst, Astute, Acheron
Spartan, Scythian, SarmathianStealth raiders
Havoc, Horror, Hazard, Harass, Terror, Tartar, Ferret, Fortune, Vigilant, Vulture, Aggressor, Arrogant, Avenger, Avalanche, Assassin, Savage, Scimitar, Scorcher, Scorpion, StormDivision troopships
Conqueror, Dictator, TyrantSalvagers
Saturn, Samhain, Sagittarius, SalsaFreihters
[Historical trade port names]
Cryotransports
[River names]
Tankers
[Lake, gulf, inner sea names]
Tugs
[Mountain names]
Later in the game, when my empire have enough astrography objects and history "store" - I use my colony names, names of dead seniour officers, names of major battles, etc.